Capacitance-variable pressure sensor

Abstract

A capacitance-variable pressure sensor is disclosed. The capacitance-variable pressure sensor includes a double layer flexible circuit board, a multi-layer ceramic capacitor, and a soft conductive pad. The multi-layer ceramic capacitor is positioned in adjacent to the soft conductive pad. The double layer flexible circuit board is configured with a through hole or a notch, and is positioned between the multi-layer ceramic capacitor and the soft conductive pad. The multi-layer ceramic capacitor is positioned above the through hole or notch, and the soft conductive pad is positioned under the through hole or notch. The multi-layer ceramic capacitor includes a first member and a second member. The first member includes an external electrode or a plurality of external electrodes. The second member includes a ceramic dielectric, and a plurality of internal electrode layers disposed inside the ceramic dielectric. Each external electrode is connected to internal electrode layers.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to a sensor, and particularly, to a capacitance-variable pressure sensor.[0002]Capacitance-variable sensor is often adopted serving as a pressure sensor in an electronic pen. A capacitance-variable sensor is in fact a plate capacitor typically consisting of a deformable flexible electrode, a metal electrode, a dielectric medium and an insulation pad. The deformable flexible electrode and the metal electrode serve as two electrodes of the plate capacitor. The metal electrode shall stay adherent to the dielectric medium, so as to avoid introduction of air therebetween and thus assuring the performance of the sensor. The insulation pad is positioned between deformable flexible electrode and the dielectric medium, and is often configured with a through hole, so as to leave an air gap between the deformable flexible electrode and the dielectric medium. The working principle can be learnt by referring to U.S. Pat. No. 5,206,78...

AI Technical Summary

Benefits of technology

[0004]To overcome the defects of the conventional technologies, the present invention provides a capacitance-variable pressure sensor which is cost-effective, simple structure, and convenient for fabrication.

Problems solved by technology

However, this also makes the fabrication process complicated and inefficient.

In addition, the metal electrode is closely positioned in contact with the dielectric medium, and air is not allowed existing therebetween.

In application, it is often achieved by directly coating a metal layer on one side of the dielectric medium, which is very complicate in processing and also increase the production cost.

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